In a variable or adjustable pitch aircraft propeller assembly of the general type disclosed in U.S. Pat. Nos. 3,380,535 and 4,097,189 which issued to the assignee of the present invention, it has been found desirable on some aircraft to reduce the tip speed of the propeller blades for reducing the noise level produced by the rotating propeller. To accomplish the blade tip speed reduction without a reduction in thrust or performance, it is necessary to increase the diameter of the propeller and to rotate the propeller at a lower RPM to provide a predetermined maximum tip speed, for example, of 850 feet per second. While it is necessary to increase the diameter of the propeller, it is also desirable to reduce the weight of the propeller, and such reduction may be obtained by constructing each propeller blade of composite materials including reinforced synthetic plastic materials in place of metal. A number of composite aircraft propeller blade assemblies have been either constructed or proposed, for example, as disclosed in U.S. Pat. Nos. 2,182,812; 2,485,827; 3,021,246; 3,554,664 and 3,664,764.